Ministers face questions on issues ranging from asset sales to the cost of roading consultants when parliament sits on Tuesday.

Opposition parties haven't had the chance to put the heat on the government during the two week recess that's seen a row brewing over Maori water rights and strife between Prime Minister John Key and the Maori Party.

Labour and the Greens are expected to use last weekend's protest marches against the partial privatisation of energy companies as ammunition for another assault on ministers.

That's tied up with the Waitangi Tribunal's hearings on the Maori Council's bid to delay the asset sales programme until claims to water rights are resolved.

Mr Key's comment - that uncertainty over water rights isn't likely to have an impact on the value of the assets when shares are floated - is sure to be probed, because opposition MPs are convinced it will.

They also think he should have kept quiet about the tribunal's hearings until a decision is reached, instead of saying the government can ignore whatever recommendation it comes up with.

The revelation on Monday that $216 million has been spent on consultants for the roads of national significance construction programme will give opposition MPs an opportunity to grill Transport Minister Gerry Brownlee.

They will want to know how much of the money was spent on planning the proposed four-lane expressway from Otaki to Levin, which the Transport Agency announced last week had been scrapped.